Nematodes that feed on corn
Multiple plant-parasitic nematodes feed on corn roots including Pratylenchus, Longidorus, Xiphinema, and Helicotylenchus spp., among others. Although prevalent, they rarely cause economic damage. Symptoms of nematode damage can occur any time during the season and include poor or uneven stands, chlorosis, stunting, and small or poorly filled ears. Often, symptoms occur in patches where nematode numbers are highest. Because these symptoms are not unique, damage is often attributed to causes such as weather, soil conditions, or fertility. Root symptoms depend on the type of nematode involved and can include stunting, root swelling and malformation, and discolored lesions. Nematode root injury with probable secondary fungal infections. Image: T. Jackson-Ziems
Injured patches of corn resulting from nematode feeding. Image: T. Jackson-Ziems
Maintain adequate soil moisture and fertility levels to reduce yield losses due to nematodes. Good weed control reduces nematode populations, as weeds can support reproduction of the nematodes. Rotation to other crops may reduce nematode numbers for a few nematode species, but most have a broad host range and can feed on many crops. Soil-applied nematicides are available, but field-wide application may not be economical. Nematode-protectant seed treatments are available.